From d497ed108e5d01584b74c61fd98ab3fc12851c3f Mon Sep 17 00:00:00 2001
From: Steven Liu <z.liu-74@student.tudelft.nl>
Date: Mon, 29 Dec 2025 12:55:00 +0100
Subject: [PATCH] fix(server): fix duplicate Ingredient present in each recipe

An issue where multiple instances of a uniquely named Ingredient are
stored in the database. This is patched by checking server-side whether
an ingredient exists before persisting it. This now correctly implements
the Many-to-Many reference.
---
 .../java/server/api/RecipeController.java     | 34 +++++++++++--------
 .../server/database/IngredientRepository.java |  2 ++
 2 files changed, 21 insertions(+), 15 deletions(-)

diff --git a/server/src/main/java/server/api/RecipeController.java b/server/src/main/java/server/api/RecipeController.java
index 3a479cb..2a56310 100644
--- a/server/src/main/java/server/api/RecipeController.java
+++ b/server/src/main/java/server/api/RecipeController.java
@@ -22,6 +22,7 @@ import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
 
+import server.database.IngredientRepository;
 import server.database.RecipeIngredientRepository;
 import server.database.RecipeRepository;
 
@@ -34,16 +35,16 @@ public class RecipeController {
     private final RecipeRepository recipeRepository; // JPA repository used in this controller
     private final SimpMessagingTemplate messagingTemplate;
     private final RecipeIngredientRepository recipeIngredientRepository;
-    private final IngredientController ingredientController;
+    private final IngredientRepository ingredientRepository;
 
     public RecipeController(RecipeRepository recipeRepository,
                             SimpMessagingTemplate messagingTemplate,
-                            IngredientController ingredientController,
+                            IngredientRepository ingredientRepository,
                             RecipeIngredientRepository recipeIngredientRepository) {
         this.recipeRepository = recipeRepository;
         this.messagingTemplate = messagingTemplate;
         this.recipeIngredientRepository = recipeIngredientRepository;
-        this.ingredientController = ingredientController;
+        this.ingredientRepository = ingredientRepository;
     }
 
     /**
@@ -80,7 +81,19 @@ public class RecipeController {
 
         return ResponseEntity.ok(recipeRepository.findAll());
     }
-
+    private Recipe saveRecipeAndDependencies(Recipe recipe) {
+        recipe.getIngredients()
+                .forEach(recipeIngredient ->
+                        recipeIngredient.setIngredient(
+                                ingredientRepository
+                                        .findByName(recipeIngredient.getIngredient().name)
+                                        .orElseGet(() -> ingredientRepository.save(recipeIngredient.getIngredient())
+                                        ))
+                );
+        recipeIngredientRepository.saveAll(recipe.getIngredients());
+        Recipe saved = recipeRepository.save(recipe);
+        return saved;
+    }
     /**
      * Mapping for <code>POST /recipe/{id}</code>.
      * Also creates the ingredient elements if they do not exist.
@@ -94,11 +107,7 @@ public class RecipeController {
         if (!recipeRepository.existsById(id)) {
             return ResponseEntity.badRequest().build();
         }
-        recipe.getIngredients().stream()
-                .map(recipeIngredient -> recipeIngredient.ingredient)
-                .forEach(ingredientController::createIngredient);
-        recipeIngredientRepository.saveAll(recipe.getIngredients());
-        Recipe saved = recipeRepository.save(recipe);
+        Recipe saved = saveRecipeAndDependencies(recipe);
         messagingTemplate.convertAndSend(Topics.RECIPES, new UpdateRecipeMessage(saved));
 
         return ResponseEntity.ok(saved);
@@ -128,12 +137,7 @@ public class RecipeController {
         if (recipeRepository.exists(Example.of(example))) {
             return ResponseEntity.badRequest().build();
         }
-        // FIXME reduce code duplication
-        recipe.getIngredients().stream()
-                .map(recipeIngredient -> recipeIngredient.ingredient)
-                .forEach(ingredientController::createIngredient);
-        recipeIngredientRepository.saveAll(recipe.getIngredients());
-        Recipe saved = recipeRepository.save(recipe);
+        Recipe saved = saveRecipeAndDependencies(recipe);
         messagingTemplate.convertAndSend(Topics.RECIPES, new CreateRecipeMessage(saved));
 
         return ResponseEntity.ok(saved);
diff --git a/server/src/main/java/server/database/IngredientRepository.java b/server/src/main/java/server/database/IngredientRepository.java
index ea32d67..df54bd3 100644
--- a/server/src/main/java/server/database/IngredientRepository.java
+++ b/server/src/main/java/server/database/IngredientRepository.java
@@ -6,9 +6,11 @@ import org.springframework.data.domain.Pageable;
 import org.springframework.data.jpa.repository.JpaRepository;
 
 import java.util.List;
+import java.util.Optional;
 
 public interface IngredientRepository extends JpaRepository<Ingredient, Long> {
     List<Ingredient> findAllByOrderByNameAsc();
     Page<Ingredient> findAllByOrderByNameAsc(Pageable pageable);
+    Optional<Ingredient> findByName(String name);
 }